Evaluate Optimal Device Ink Limits

From ColorWiki

Compare the gamut of a proofing system to a simulation profile to determine the best ink limits for the proofer.

Good for setting inkjet channel limits prior to profile generation.

Limiting inking levels improves profile accuracy. This test ensures that you don't limit too much - for example, shrinking the gamut so it cannot contain the simulation profile.

This test opens the two profiles into the grapher and activates the Channel Constraints feature. The user then uses the Channel Constraints sliders to reduce the ink used in the proofing profile. When the gamut of the proofing profile is reduce until it just contains the simulation profile, make a note of the channel constraints numbers and apply those to the RIP. See the ColorSmarts Guide Summary window (which shows up at the end of the test) for further instructions.

Primarily, this test is intended for press operators who need to know the best ink limit for their proofing printer. Many printers used for creating hard proofs are inkjets which have a wide gamut compared to the presses they are intended to proof. Since this extra gamut is not necessary, limiting the ink going to the proofer can help save money on ink as well as make proofs more stable, color-wise.

While this is primarily intended for CMYK profiles, the constrain channels feature is also available for RGB profiles, to help learn or demonstrate how red, green and blue contribute to the shape and makeup of the profile.